Part XIII — Practice

Chapter 13: Mixed Practice Set — All Technical Topics (50 MCQs)

This chapter mixes questions from every technical chapter in this book, in exam-realistic random order.

1. Newton's Second Law of Motion is expressed as:
   (a) F = ma (b) F = m/a (c) F = m + a (d) F = a/m
2. The coefficient of friction (μ) is defined as:
   (a) The ratio of limiting friction force to normal reaction (b) The ratio of normal reaction to friction force (c) The product of mass and acceleration (d) The ratio of stress to strain
3. Hooke's Law states that, within the elastic limit:
   (a) Stress is inversely proportional to strain (b) Stress is directly proportional to strain (c) Stress is independent of strain (d) Strain is always zero
4. The Modulus of Elasticity of steel is approximately:
   (a) 2×10⁵ N/mm² (b) 2×10³ N/mm² (c) 2×10⁷ N/mm² (d) 25–35 GPa
5. Poisson's Ratio for common metals typically ranges between:
   (a) 0.05–0.10 (b) 0.25–0.35 (c) 0.50–0.75 (d) 1.0–1.5
6. Factor of Safety (FoS) is defined as the ratio of:
   (a) Working stress to ultimate/yield strength (b) Ultimate/yield strength to allowable/working stress (c) Strain to stress (d) Force to velocity
7. The Zeroth Law of Thermodynamics forms the basis for defining:
   (a) Pressure (b) Temperature (c) Volume (d) Density
8. The First Law of Thermodynamics is expressed as:
   (a) ΔU = Q − W (b) ΔU = Q + W (c) ΔU = Q × W (d) ΔU = W − Q
9. The Kelvin-Planck statement of the Second Law asserts that:
   (a) No engine can convert heat completely into work in a cyclic process (b) All engines are 100% efficient (c) Heat always flows from cold to hot spontaneously (d) Entropy always decreases
10. The Carnot cycle efficiency formula is:
    (a) η = 1 − (T_L/T_H) (b) η = T_L/T_H (c) η = T_H/T_L (d) η = 1 + (T_L/T_H)
11. The Otto cycle is the idealised air-standard cycle for:
    (a) Compression-ignition (diesel) engines (b) Spark-ignition (petrol) engines (c) Steam power plants (d) Gas turbines exclusively
12. The Rankine cycle is the idealised cycle used to model:
    (a) Petrol engines (b) Diesel engines (c) Steam power plants (d) Refrigeration systems only
13. A four-bar mechanism consists of how many rigid links connected in a closed loop?
    (a) Two (b) Three (c) Four (d) Six
14. The slider-crank mechanism converts:
    (a) Reciprocating motion into oscillating motion only (b) Rotary motion into reciprocating motion, or vice versa (c) Linear motion into linear motion (d) Nothing
15. Spur gears have teeth that are:
    (a) Parallel to the axis of rotation (b) Angled relative to the axis (c) Used only for intersecting shafts (d) Used only for very high reduction ratios
16. Bevel gears are primarily used to connect:
    (a) Parallel shafts (b) Intersecting shafts, typically at 90° (c) Non-intersecting, non-parallel shafts only (d) Shafts that never need power transmission
17. A flywheel's primary function is to:
    (a) Regulate mean engine speed over a period of varying load (b) Store rotational kinetic energy to smooth out instantaneous speed fluctuations (c) Convert reciprocating motion into rotary motion exclusively (d) Measure engine torque directly
18. A governor's primary function is to:
    (a) Store kinetic energy for one engine cycle only (b) Regulate the mean speed of an engine over a period of varying load (c) Provide gear reduction (d) Measure temperature
19. The standard density of water is approximately:
    (a) 100 kg/m³ (b) 500 kg/m³ (c) 1000 kg/m³ (d) 2000 kg/m³
20. Bernoulli's Theorem states pressure head, velocity head, and elevation head sum to a value that is:
    (a) Zero (b) Constant along a streamline (c) Always increasing (d) Dependent only on pipe material
21. A centrifugal pump uses a rotating impeller to convert kinetic energy into:
    (a) Pressure energy (b) Chemical energy (c) Thermal energy directly (d) Nuclear energy
22. A reciprocating pump operates on which basic principle?
    (a) Centrifugal force (b) Positive displacement, via a piston/plunger (c) Magnetic induction (d) Bernoulli's principle exclusively
23. A Pelton wheel is classified as:
    (a) A reaction turbine (b) An impulse turbine (c) A centrifugal pump (d) A reciprocating pump
24. A Francis turbine is best suited for:
    (a) High head, low flow-rate applications (b) Medium head, medium flow-rate applications (c) Only zero-flow conditions (d) Compressed air applications only
25. A Kaplan turbine is best suited for:
    (a) High head, low flow-rate applications (b) Low head, high flow-rate applications (c) Medium head applications only (d) Only impulse-type operation
26. Sand casting typically uses which type of mould material?
    (a) Steel dies exclusively (b) A sand mould, often "green sand" (c) Ceramic shells exclusively (d) Only wax patterns
27. Die casting is particularly suited for:
    (a) One-off, low-volume production (b) High-volume production of precision parts, often non-ferrous alloys (c) Only ferrous metals (d) Only very large components
28. Investment casting (lost-wax casting) is valued for:
    (a) Very high dimensional accuracy and intricate detail (b) Being the cheapest process for large simple castings (c) Requiring no pattern at all (d) Using only sand moulds
29. Shielded Metal Arc Welding (SMAW) generates heat via:
    (a) A gas flame (b) An electric arc between electrode and workpiece (c) Electrical resistance heating under pressure only (d) Friction alone
30. Resistance (spot) welding is widely used in:
    (a) Automotive body sheet-metal assembly (b) Casting large iron blocks (c) Cutting threads on bolts (d) Measuring dimensions
31. A lathe machine is primarily used for:
    (a) Producing flat surfaces and slots (b) Turning cylindrical parts by rotating the workpiece against a cutting tool (c) Producing round holes only (d) Casting molten metal
32. A milling machine uses:
    (a) A rotating multi-point cutter against a workpiece (b) A stationary tool only (c) Molten metal poured into a mould (d) An electric arc for cutting
33. A vernier caliper typically has a least count of approximately:
    (a) 0.02mm (b) 0.2mm (c) 2mm (d) 20mm
34. A micrometer (screw gauge) typically provides a least count of approximately:
    (a) 0.1mm (b) 0.01mm (c) 1mm (d) 10mm
35. Spark-Ignition (SI) engines typically operate on which idealised thermodynamic cycle?
    (a) Diesel cycle (b) Otto cycle (c) Rankine cycle (d) Brayton cycle
36. In a CI (diesel) engine, ignition occurs due to:
    (a) A spark plug igniting a pre-mixed charge (b) Air compressed to a high temperature that spontaneously ignites injected fuel (c) An external flame source (d) Electrical resistance heating
37. A four-stroke engine completes one power stroke per:
    (a) One crankshaft revolution (b) Two crankshaft revolutions (c) Four crankshaft revolutions (d) Half a crankshaft revolution
38. Compression ratio is defined as the ratio of:
    (a) Clearance volume to total cylinder volume (b) Total cylinder volume to clearance volume (c) Bore to stroke (d) Power to torque
39. Mean Effective Pressure (MEP) is best described as:
    (a) The maximum instantaneous pressure (b) A theoretical average pressure producing the same net work as the actual varying pressure (c) The exhaust gas pressure only (d) Atmospheric pressure at sea level
40. In a thermal (steam) power plant, the boiler's primary function is to:
    (a) Condense steam back to water (b) Generate heat, converting water to high-pressure steam (c) Drive the generator directly (d) Store fuel
41. A thermal power plant's basic cycle is essentially a practical implementation of the:
    (a) Otto cycle (b) Diesel cycle (c) Rankine cycle (d) Carnot cycle exactly
42. A nuclear power plant generates heat primarily through:
    (a) Combustion of coal (b) Controlled nuclear fission (typically of uranium-235) (c) Solar radiation (d) Wind turbine rotation
43. RRB JE examinations apply negative marking of:
    (a) 1/4 mark (b) 1/3 mark (c) 1/2 mark (d) No negative marking
44. The Technical Abilities section in RRB JE CBT 2 typically carries how many marks?
    (a) 50 (b) 75 (c) 100 (d) 120
45. Tensile stress results from a force that:
    (a) Pulls/stretches a material (b) Pushes/squeezes a material (c) Causes layers to slide past each other (d) Causes rotation only
46. Shear stress results from forces that:
    (a) Pull a material apart uniformly (b) Cause layers to slide relative to each other (c) Compress a material uniformly (d) Have no effect on material layers
47. Worm gears are particularly valued for providing:
    (a) Very high gear reduction ratios in a compact arrangement (b) The lowest possible reduction ratio (c) No self-locking capability ever (d) Parallel shaft connection only
48. Laminar pipe flow is generally associated with Reynolds Numbers:
    (a) Below ~2000 (b) Above ~4000 (c) Exactly 3000 (d) Above 10,000
49. Limits, fits, and tolerances in manufacturing primarily ensure:
    (a) Proper assembly and interchangeability of mating parts (b) Reduced material cost only (c) Increased casting temperature (d) Faster welding speed
50. A two-stroke engine, compared to a four-stroke engine, generally provides:
    (a) Less power per cycle for a given size (b) More power per cycle for a given size, but often less fuel efficiency (c) Identical efficiency in all cases (d) No practical power output

Answer Key

1.(a)

2.(a)

3.(b)

4.(a)

5.(b)

6.(b)

7.(b)

8.(a)

9.(a)

10.(a)

11.(b)

12.(c)

13.(c)

14.(b)

15.(a)

16.(b)

17.(b)

18.(b)

19.(c)

20.(b)

21.(a)

22.(b)

23.(b)

24.(b)

25.(b)

26.(b)

27.(b)

28.(a)

29.(b)

30.(a)

31.(b)

32.(a)

33.(a)

34.(b)

35.(b)

36.(b)

37.(b)

38.(b)

39.(b)

40.(b)

41.(c)

42.(b)

43.(b)

44.(c)

45.(a)

46.(b)

47.(a)

48.(a)

49.(a) 50.(b)